copyin() or copyout().
uvm_useracc() tells us whether the mapping permissions allow access to
the desired part of an address space, and many callers assume that
this is the same as knowing whether an attempt to access that part of
the address space will succeed. however, access to user space can
fail for reasons other than insufficient permission, most notably that
paging in any non-resident data can fail due to i/o errors. most of
the callers of uvm_useracc() make the above incorrect assumption. the
rest are all misguided optimizations, which optimize for the case
where an operation will fail. we'd rather optimize for operations
succeeding, in which case we should just attempt the access and handle
failures due to insufficient permissions the same way we handle i/o
errors. since there appear to be no good uses of uvm_useracc(), we'll
just remove it.
(1) split the single list of pages allocated to a pool into three lists:
completely full, partially full, and completely empty.
there is no longer any need to traverse any list looking for a
certain type of page.
(2) replace the 8-element hash table for out-of-page page headers
with a splay tree.
these two changes (together with the recent enhancements to the wait code)
give us linear scaling for a fork+exit microbenchmark.
mbuf chains which are recycled (e.g., ICMP reflection, loopback
interface). A consensus was reached that such recycled packets should
behave (more-or-less) the same way if a new chain had been allocated
and the contents copied to that chain.
Some packet tags may in future be marked as "persistent" (e.g., for
mandatory access controls) and should persist across such deletion.
NetBSD as yet hos no persistent tags, so m_tag_delete_nonpersistent()
just deletes all tags. This should not be relied upon.
This should fix PR 23418 which was also reported by Thomas Klausner and
Ian Fry (who also provided core dumps for analysis - thanks!).
Also g/c sa_yieldcall since it's now safe to put LWPs back into the cache.
Also return stacks in failure case.
of the sibling list so that find_stopped_child can be optimised to avoid
traversing the entire sibling list - helps when a process has a lot of
children.
- Modify locking in pfind() and pgfind() to that the caller can rely on the
result being valid, allow caller to request that zombies be findable.
- Rename pfind() to p_find() to ensure we break binary compatibility.
- Remove svr4_pfind since p_find willnow do the job.
- Modify some of the SMP locking of the proc lists - signals are still stuffed.
Welcome to 1.6ZF
specifically, don't keep a stale pointer in fd_ofiles.
it isn't needed anymore as fd allocation is now done using bitmaps.
- clean up dupfdopen() a little.
- don't call fd_used() unnecessarily.
the not-entered symbols will be found anyway but via a linear-search.
This only happens if something is wrong when linking the kernel.
Fixes problems reported on port-hp700.
Remove p_raslock and rename p_lwplock p_lock (one lock is enough).
Simplify window test when adding a ras and correct test on VM_MAXUSER_ADDRESS.
Avoid unpredictable branch in i386 locore.S
(pad fields left in struct proc to avoid kernel bump)
combined. Also prepare for adding VP repossession later.
- kern_sa.c: sa_yield/sa_switch: detect if there are pending unblocked
upcalls.
- kern_sa.c: sa_unblock_userret/sa_setwoken: queue LWPs about to invoke
an unblocked upcall on the sa_wokenq. put queued LWPs in a state where
they can be put in the cache. notify LWP on the VP about pending
upcalls.
- kern_sa.c: sa_upcall_userret: check sa_wokenq for pending upcalls,
generate unblocked upcalls with multiple event sas
- kern_sa.c: sa_vp_repossess/sa_vp_donate: g/c, restore original
sa_vp_repossess
General idea: only consider the LWP on the VP for signal delivery, all
other LWPs are either asleep or running from waking up until repossessing
the VP.
- in kern_sig.c:kpsignal2: handle all states the LWP on the VP can be in
- in kern_sig.c:proc_stop: only try to stop the LWP on the VP. All other
LWPs will suspend in sa_vp_repossess() until the VP-LWP donates the VP.
Restore original behaviour (before SA-specific hacks were added) for
non-SA processes.
- in kern_sig.c:proc_unstop: only return the LWP on the VP
- handle sa_yield as case 0 in sa_switch instead of clearing L_SA, add an
L_SA_YIELD flag
- replace sa_idle by L_SA_IDLE flag since it was either NULL or == sa_vp
Also don't output itimerfire overrun warning if the process is already
exiting.
Also g/c sa_woken because it's not used.
Also g/c some #if 0 code.
we pass via sigctx, so that it guaranteed that the memory wouldn't be
paged out at the time the signal arrives
potential problem pointed out by YAMAMOTO Takashi
generate unblocked upcalls in sa_unblock_userret(), before signal
delivery/p_userret handling in userret().
Also defer getting state for preempted upcalls because on some ports
preemption can happen between sa_unblock_userret() and sa_upcall_userret().
its state is saved:
- don't sa_putcachelwp() in sa_vp_repossess/sa_vp_donate
- only defer saving the event LWP's state
- sa_putcachelwp() after the interrupted LWP's state is saved
-obey ELF_LINK_ADDR in ELF_load_file()
-set ELF_LINK_ADDR in the probe() function if needed
-make ELF_NULL_ADDR the default, so that probe() functions dont need
to set it explicitely
-allocate buffer for interpreter name only if needed
initialized. Update the txp(4) to compensate.
- Statically initialize the TCP timer callout handles in the tcpcb
template. We still use callout_setfunc(), but that call is now much
less expensive. Add a comment that the compiler is likely to unroll
the loop (so don't sweat that it's there).
separately from the bufpages, so that it would be possible to eventually
make their limits changeable in runtime
make static all local variables which do not need to be exported to other
kernel parts
set using a pointer, to save couple bytes in struct sigctx
also fix fallout from recent lwp_wakeup() change, where we failed to properly
detect if tsleep() returned as result of lwp_wakeup() or signal outside
our wait set; could have caused problems for threaded apps using sigwait(2)
et.al.
chs